1. Field of the Invention
The present invention relates to an electrophotographic photoconductor.
2. Discussion of the Background
Inorganic photoconductive materials such as selenium, amorphous silicon and zinc oxide have been used for an electrophotographic photoconductor because they have good sensitivity and durability. However, they have one or more drawbacks such as being toxic and having high manufacturing cost due to low productivity. Therefore, currently organic photoconductors have been developed which are atoxic and have potential of being able to be easily mass-manufactured at a relatively low manufacturing cost using a simple coating method.
These organic photoconductors have advantages such as being atoxic and having low manufacturing cost, however, they have drawbacks in point of sensitivity, stability in various environments and durability, and particularly photoconductors having good stability when used in various environments and good durability are strongly desired. In addition, particle size of toner becomes finer and finer because there are recently many demands such as color reproduction and high quality reproduction. Therefore, a need exists for a photoconductor having high toner transfer efficiency and good toner releasability (ability to release toner therefrom).
In attempting to improve these drawbacks, photoconductors which include a silicone resin or a silicone including polymer in a charge transporting layer which is formed on the surface thereof (Japanese Laid-Open Patent Publications No. 57-64243, 60-256146, 61-95358, 61-132954 and 61-219047). However, these photoconductors have drawbacks such as poor rub resistance and increase of residual surface potential causing fouling of background of recorded images when repeatedly used. In addition, a photoconductor which includes, in a charge transporting layer which is formed on the surface thereof, hydrodiene polysiloxane (Japanese Laid-Open Patent Publications No. 54-3534) or epoxy modified silicone and silicone having an active hydrogen (Japanese Laid-Open Patent Publications No. 5-158273) has been proposed, however, improvement in toner transfer efficiency and toner releasability is insufficient and further they have a drawback of increase of residual surface potential when repeatedly used. Thus, these conventional photoconductors which include a silicone including polymer and the like have poor durability and therefore they are desired to be improved.
Because of these reasons, a need exists for a photoconductor which has good durability without increase of residual surface potential when repeatedly used, and which further has high toner transfer efficiency and good toner releasability.